Insulator for an electric fence



FIG. 1 is a perspective view of an insulator for an electric fence showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a front elevational view thereof; and,

FIG. 5 is a side elevational view thereof. 

The ornamental design for an insulator for an electric fence, as shown and described. 